The present invention relates generally to radio frequency identification systems, and more particularly, to automatic interrogation technology on multiple bandwidths and multiple frequencies.
Radio Frequency Identification (RFID) is a type of automated data collection technology. Because of its ability to track moving objects, Radio Frequency Identification is also used in many applications including livestock identification and automated vehicle identification (AIR) systems. Wireless automated data collection systems allow for noncontact reading and consequently are effective in manufacturing and other hostile environments and can be used as a replacement for bar code labels.
RFID systems basically include three components: an antenna or coil, a transceiver (with decoder), and a transponder, commonly called an RF tag, that is electronically programmed with unique information.
In operation, the antenna emits radio signals to activate the tag and read and write data to the tag. Antennas are the conduits between the tag and the transceiver. Antennas are available in a variety of shapes and sizes; for example, the antenna can be built into a door frame to receive tag data from persons or things passing through the door, or mounted on a pole or overhead frame to track traffic passing by on a freeway. The electromagnetic field produced by an antenna can be constantly present when multiple tags are expected continually. If constant interrogation isn""t required, the field can be activated by a sensor device.
The antenna is typically packaged with the transceiver and decoder to become a reader, often called an interrogator. The interrogator can be configured either as a handheld or a fixed-mount device. The interrogator emits radio waves in ranges of anywhere from one inch to 100 feet or more, depending upon the power output and of the interrogator and the radio frequency used. When an RFID tag passes through the electromagnetic zone, the tag detects the interrogator""s activation signal. The interrogator decodes the data encoded in the tag""s integrated circuit (silicon chip) and the data is passed to a host computer for processing.
RFID tags come in a wide variety of shapes and sizes. Animal tracking tags, inserted beneath the skin, can be as small as a pencil lead in diameter and one half inch in length. Tags can be screw-shaped to identify trees or wooden items, or credit-card shaped for use in access applications. The anti-theft hard plastic tags attached to merchandise in stores are also RFID tags, as are heavy-duty five by four by two inch rectangular transponders used to track intermodal containers, or heavy machinery, trucks, and railroad cars for maintenance and tracking applications.
There are two categories of tags: active and passive. Active tags are powered by an internal battery and are typically read/write, i.e. tag data can be rewritten and/or modified. An active tag""s memory size varies according to application requirements; some systems operate with up to one megabyte of memory. In a typical read/write RFID work-in-process system, a tag might give a machine a set of instructions, and the machine would then report its performance back to the tag. This encoded data would then become part of the tagged part""s history.
Passive RFID tags operate without a separate internal power source and obtain operating power generated from the reader. Passive tags are consequently much lighter than active tags, less expensive, and offer a virtually unlimited operational lifetime. The trade-off is that passive tags have shorter read ranges than active tags and require a higher-powered reader. Passive tags are typically read-only and are programmed with a unique set of data (usually 32 to 128 bits) that cannot be modified. Read-only tags most often operate as a license plate into a database, in the same way as linear bar codes reference a database containing modifiable product-specific information.
There are many RFID systems having many frequency ranges. Low-frequency (30 to 500 KHz) systems have short reading ranges and lower system costs. Low-frequency systems are most commonly used in security access, asset tracking, and animal identification applications. High-frequency (850 to 950 MHz and 2.4 to 2.5 GHz) systems, offering long read ranges (greater than 300 feet) and high reading speeds, are used for such applications as railroad car tracking and automated toll collection. However, the higher performance of high-frequency RFID systems incurs higher system costs.
The significant advantage of all types of RFID systems is the non-contact, non-line-of-sight nature of the technology. Tags can be read through a variety of substances such as snow, fog, ice, paint, crusted grime, and other visually and environmentally challenging conditions, where bar codes or other optically read technologies would be useless. RFID tags can also be read in challenging circumstances at remarkable speeds, in most cases responding in less than 100 milliseconds. The read/write capability of an active RFID system is also a significant advantage in interactive applications such as work-in-process or maintenance tracking. Though it is a costlier technology (compared with bar code), RFID has become indispensable for a wide range of automated data collection and identification applications that would not be possible otherwise.
The proliferation of incompatible RFID systems has caused problems. Each RFID vendor offers a proprietary system, with the result that various applications and industries have standardized on different vendors"" competing frequencies and protocols. The current state of RFID standards is severe Balkanizationxe2x80x94standards based on incompatible RFID systems exist for rail, truck, air traffic control, and tolling authorities usage, as well as for the U.S. Intelligent Transportation System and the DOD""s Total Asset Visibility system, among other special-interest applications. Although a number of organizations have been working to address and hopefully bring about some commonality among competing RFID systems, there is still no common industry standards. Thus, there is a pressing need to integrate the various RFID systems so that various assets can be tracked by a single system. The inventors are not aware of a single interrogator that can perform multi-bandwidth interrogation. Further, current interfaces to remotely access data are very complex or non-existent.
It is, therefore, an object of the present invention to provide a method and apparatus which assets distributed around the world can be located in real time or near real time.
It is another object of the present invention to provide an interrogator which can read/write to tags from different manufacturers on multiple band widths and on multiple frequencies.
It is another object of the present invention to provide a system which can update a data warehouse which includes information about each of the distributed assets in near real time.
It is another object of the present invention to be able to update a corporate database across the Internet.
These and other objects of the present invention are achieved by providing a smart interrogator which can communicate with RF tags on multiple frequencies and bandwidths. Advantageously, the smart interrogator can communicate with tags from various manufacturers and thus permits assets to be tracked even if the assets are being tracked using tags from different manufacturers. This eliminates the need to track assets using many different interrogators. The smart interrogators communicate with a logistics server via the internet using transferable agents. The agents forward information from the tag to the logistics server. A Java database connection (JDBC) is established between the logistics server and the smart interrogator. The log server records transaction information in the data warehouse and forwards asset data to registered client databases. A client can query the logistics server to determine the whereabouts of a particular asset. The logistics server can spawn a transferable agent to locate the asset. If the asset cannot be located while the client is logged onto the logistics server, then the transferable agent will push the information back to the logistics server. The client will then be updated with the information pushed back by the transferable agent. The transferable agents can be used to forward information from the logistics server to other servers and clients.
The foregoing objects are also achieved by a method of locating assets over the internet with each asset having an associated tag. Tags are interrogated on multiple frequencies. Information about the associated asset is transmitted, from one or more of the tags. The transmitted information is received and forwarded over the internet to registered client databases.
The foregoing objects are also achieved by an article, comprising at least one sequence of machine executable instructions. A medium bears the executable instructions in machine readable form wherein execution of the instructions by one or more processors causes the one or more processors to interrogate tags on multiple frequencies. Information about the associated asset is transmitted from one or more of the tags. The transmitted information is received and forwarded over the internet to registered client databases.
The article could also comprise instructions which cause the one or more processors to set up a database connection at a location wherein the forwarded information is received at the database connection and deploy agents to forward the information over the internet.
The foregoing objects are also achieved by a computer architecture which includes interrogating means for interrogating tags on multiple frequencies. Transmitting means are provided, for transmitting from one or more of the tags, information about the associated asset. Receiving means are provided for receiving the transmitted information and forwarding the received information over the internet to registered client databases.
The computer architecture could also comprise setting up means for setting up a database connection at a location wherein the forwarded information is received at the database connection and agent means for deploying agents to forward the information over the internet.
The foregoing objects are also achieved by a computer system comprising a processor and a memory coupled to the processor, the memory having stored therein sequences of instructions, which, when executed by said processor, cause said processor to perform the steps of interrogating tags on multiple frequencies and transmit, from one or more of the tags, information about the associated asset and receive the transmitted information and forward the received information over the internet to registered client databases.
The computer system could also comprise instructions, which, when executed by said processor, cause said processor to perform the steps of setting up a database connection at a location wherein the forwarded information is received at the database connection and deploying agents to forward the information over the internet.
Still other objects and advantage of the present invention will become readily apparent to those skilled in the art from following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive.